"Taken together, these points make the 12-nucleotide insertion that has created a novel furin cleavage site in SARS-CoV-2—so uncharacteristic of SARS-like viruses—look extremely suspicious.

The behavior of the WIV and its scientists also raises any number of troubling questions. The viral strain RaTG13 is a case in point. First collected by the WIV in 2013, RaTG13 was sequenced in 2018, but not disclosed until after the SARS-CoV-2 outbreak. In their initial disclosure, the WIV failed to mention how or when they came to possess RaTG13, failed to indicate that it was previously called Ra4991, failed to cite their own 2016 paper first mentioning it, and seemed to imply that they only sequenced the sample after the outbreak. This does not seem like the behavior of scientists trying their utmost to establish how a Laotian or Yunnan virus came to cause an outbreak in Wuhan.

None of these points is in itself conclusive, but the circumstantial evidence is more suggestive of a lab leak than an act of nature."